1. Field of the Invention
The present invention relates to a washing machine with an agitator, and more particularly to a washing machine with an agitator for rotating washing water accommodated in a washing tub to wash laundry.
2. Description of the Prior Art
Generally, washing operation of a washing machine consists of a plurality of processes, that is, a water supplying process for supplying washing water into a washing tub, a washing process for washing laundry with the washing water supplied through the water supplying process, a rinsing process for rinsing laundry washed through the washing process, and a dehydrating process for dehydrating laundry rinsed through the rinsing process.
A general washing machine which performs the above washing operation has, as shown in FIG. 1, an outer tub 110 installed in a casing 100, a washing tub 120 installed in the outer tub 110 for accommodating laundry and water, a pulsator 130 mounted on the bottom surface of the washing tub 120 for rotating the washing water in the washing tub 120, a driving motor 140 disposed under the outer tub 110 for driving the pulsator 130, and a gear assembly 150 for transmitting the power of the driving motor 140 selectively to the pulsator 130 and the washing tub 120.
The outer tub 110 has a cylindrical shape which allows a rotating water flow generated during washing operation and is suspended in the casing 100 by a suspending bar 180. One end of the suspending bar 180 is connected to a damper 160 attached on a low portion of surface of the outer tub 110, and the other end of it 180 is fixed on the upper portion of inner wall of the casing 100. Also, the washing tub 120 having a cylindrical shape is installed in the outer tub 110 rotatively. A plurality of holes 170 are formed on the wall of the washing tub 120 such that the washing water supplied into the washing tub 120 flows to the side of the outer tub 110 through the holes 170. Accordingly, levels of water in the washing tub 120 and the outer tub 110 are equal. Also, the dirty washing water and any sediments which are generated from the washing water during the dehydrating process are deposited to the outer tub 110 through the holes 170. And, the pulsator 130 installed on the bottom surface of the washing tub 120 rotates clockwise and counterclockwise by the driving motor 140 and the gear assembly 150.
In the washing process, the power of the driving motor 140 is transmitted to the pulsator 130 via the gear assembly 150, thereby the pulsator 130 rotates such that a water flow rotating in the washing tub 120 is formed. The washing process of laundry accommodated in the washing tub 120 by the rotating water flow generated by the pulsator 130 is performed. In the dehydrating process, the power of the driving motor 140 is transmitted to the washing tub 120 and the pulsator 130 via the gear assembly 150 such that the washing tub 120 and the pulsator 130 rotate integrally at high speed. At this time, by the centrifugal force generated by the rotation of the pulsator 130, the dehydrating process is performed. Also, when the pulsator 130 rotates clockwise and counterclockwise, the outer tub 110 strongly vibrates due to the rotation of the washing tub 120 and the washing water. The vibration is alleviated by the damper 160 attached on the outer surface of the outer tub 110.
As described above, in the conventional washing machine, as indicated by the direction of the arrow in FIG. 1, the laundry moves to the central portion of the washing tub 120 to be twisted by the rotating water flow generated when the pulsator 130 rotates clockwise and counterclockwise. Therefore, efficiency of the washing machine is reduced. That is, when the rotating water flow is generated in the washing tub 120, the laundry rotates to be scrubbed by the rotating water flow, thereby the washing process is performed. At this time, the laundry moves to the central portion of the washing tub 120 to be twisted by the rotating water flow. Since the laundry once twisted is not likely to be scrubbed even by the rotating water flow, too much washing time is wasted and the efficiency of washing declines.
Also, since the pulsator 130 rotates in the lower portion of the washing tub 120, the strong water flow is generated in the lower portion of the washing tub 120 so the water flow as a result becomes weak at the upper portion of the washing tub 120. Accordingly, when the amount of the water accommodated in the water tub 120 is great, the laundry is efficiently washed in the lower portion of the washing tub 120, but contrarily the laundry is not efficiently washed in the upper portion of the washing tub 120. Moreover, according to the tendency for larger sized washing machines, the washing tub 120 with large capacity is adopted, so the laundry is not efficiently washed by the pulsator 130 installed in the bottom surface of the washing tub 120.